The present invention pertains to a method for manufacturing a multi-part component so that it dampens vibration and noise when it is subject to forces.
There are many multi-part components that are used in applications which subject the components to forces and, thus, cause the components to vibrate or make noise. Common examples include the use of multi-sheet laminate steel parts in vehicles and commercial airplanes.
With respect to vehicles, a major concern has been noise and vibration in the passenger compartment caused by the vibration energy of different systems in the vehicle, such as engine, power train and climate control systems. In particular, components such as oil pan assemblies, cam covers and front covers are subjected to various forces that cause noise and vibration. For example, in oil pan assemblies, the configuration of a windage tray and other associated components of the pan assembly and their proximity to the engine often cause the assembly to vibrate. As a result, undesirable noise and vibration (in the form of waves) travel to the interior of the vehicle, which can cause discomfort. Attempts have been made to dampen the noise and vibration in order to provide high-quality vehicles that remain quiet, promoting increased customer satisfaction.
In one known method, a rubber material is positioned between two sheets of metallic material, and the sheets of metal and rubber material are rolled together to form a sandwich (metal-rubber-metal) or laminate material. The laminate is then stamped and cut into a desired shape.
One problem with this known method, is that it results in inadequate support and a wastage of material. To dampen vibration and noise, the rubber need only be applied to strategic areas of the part. In some areas, primarily the perimeter and close to ribs formed in the part, more rubber is required. More rubber is required along the perimeter because it is at these locations that much of the vibrational forces are generated by the momentum of the component. The known method of manufacturing a multi-part component uses an equal amount of rubber material throughout the part providing little control over the amount of rubber material used in different areas. As a result, too much rubber material is used where it is not needed and insufficient material is used where it is most needed, e.g., the perimeter.
Moreover, when the component manufactured using the known method is used in assemblies that are exposed to oil, additional problems arise. The rubber material used between the sheets is typically a thermoplastic material that is spongy, and is made from a urethane matrix. The spongy material is inadequately oil resistant, temperature resistant and compression set resistant and, as a result, is susceptible to decomposing upon exposure to oil. Vibrational dampening capabilities are, therefore, compromised.
Further, to ensure that the metal sheet that is held together with the rubber material remains aligned and connected, holes or slots are formed within the sheets. The rubber material protrudes into the holes or slots to help maintain alignment and connection. But, when used in applications having exposure to oil, the rubber material decomposes and the oil seeps through the holes or slots, again, compromising the integrity of the structure.
Accordingly, there exists a need for an improved method for manufacturing multi-part components that can dampen vibration and noise caused by exposure to forces. Desirably, the improved method allows for improved manufacturing efficiency while still providing improved dampening.